4 Pieces Child Proof Window Door Locks, This is a kind of sliding patio door latches, window bolt safety lock, prevents accidental window opening, extra security for your child and window, it is suggested that the locks be installed at the top and bottom for maximum security, Home Security System Upgrade 8 Universal Keys Supplied with 8 universal keys, 4 sliding door locks, each sliding door lock comes with 2 keys, the keys are universal. Easy Installation Easy to install the locks and convenient to use, supplied with all security fixing accessories, includes caps, stainless steel screws Application suitable for most swing or sliding doors and windows, this design is very useful for home, schools and other children's places.